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<hr>
<span id="Controlling-Names-Used-in-Assembler-Code"></span><h4 class="subsection">6.47.4 Controlling Names Used in Assembler Code</h4>
<span id="index-assembler-names-for-identifiers"></span>
<span id="index-names-used-in-assembler-code"></span>
<span id="index-identifiers_002c-names-in-assembler-code"></span>

<p>You can specify the name to be used in the assembler code for a C
function or variable by writing the <code>asm</code> (or <code>__asm__</code>)
keyword after the declarator.
It is up to you to make sure that the assembler names you choose do not
conflict with any other assembler symbols, or reference registers.
</p>
<span id="Assembler-names-for-data"></span><h4 class="subsubheading">Assembler names for data</h4>

<p>This sample shows how to specify the assembler name for data:
</p>
<div class="example">
<pre class="example">int foo asm (&quot;myfoo&quot;) = 2;
</pre></div>

<p>This specifies that the name to be used for the variable <code>foo</code> in
the assembler code should be &lsquo;<samp>myfoo</samp>&rsquo; rather than the usual
&lsquo;<samp>_foo</samp>&rsquo;.
</p>
<p>On systems where an underscore is normally prepended to the name of a C
variable, this feature allows you to define names for the
linker that do not start with an underscore.
</p>
<p>GCC does not support using this feature with a non-static local variable 
since such variables do not have assembler names.  If you are
trying to put the variable in a particular register, see 
<a href="Explicit-Register-Variables.html">Explicit Register Variables</a>.
</p>
<span id="Assembler-names-for-functions"></span><h4 class="subsubheading">Assembler names for functions</h4>

<p>To specify the assembler name for functions, write a declaration for the 
function before its definition and put <code>asm</code> there, like this:
</p>
<div class="example">
<pre class="example">int func (int x, int y) asm (&quot;MYFUNC&quot;);
     
int func (int x, int y)
{
   /* <span class="roman">&hellip;</span> */
</pre></div>

<p>This specifies that the name to be used for the function <code>func</code> in
the assembler code should be <code>MYFUNC</code>.
</p>



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